The present invention relates to a water delivery machine, and particularly such a machine for use with a self-propelled linear irrigator. The machine delivers water automatically and continuously from a pressurized main line to the linear system as the system moves down the field. The machine of the present invention is for use with a pressurized main line having risers or connectors spaced along its length. The machine has couplers carried by carts whereby the couplers alternately connect and disconnect to the risers as the machine and the linear system moves down the field. At least one of the couplers is always connected to a riser so that water, under pressure, is delivered continuously to the linear system. Moreover, this is accomplished without interrupting the operation of the linear system itself.
By way of background, there are two chief problems associated with a linear irrigation system: one is with supplying water to the system as it moves over the field, and the other is with guiding the system over the field to be irrigated. The present invention addresses both of these problems.
Various techniques are known for delivering water to a linear system. One category includes an open ditch extending the length of the field where water is pumped from the ditch to the linear system as it moves to irrigate the field. Another category is the pressurized system where a pressurized main line extends the length of the field and some means are provided for delivering water from the pressurized main line to the linear system. An example of such a pressurized system is the hose drag machine where a flexible hose from the linear system is connected to a riser or hydrant of the pressurized main line so that water is delivered through the hose to the system. One disadvantage of commercial versions of such systems is that the hose must be manually disconnected from one riser and reconnected to the next riser. A patent that addresses this problem is Purtell Patent 3,444,941, wherein the hose is connected to a coupler carried by a single cart which automatically moves from riser to riser as the linear system traverses the field. However, the technique shown by the Purtell patent requires interruption of both the movement of the linear system and the delivery of water as the cart moves from riser to riser.
The present invention is in the pressurized category which uses spaced risers along the pressurized main line, and where water is delivered to the linear system without interruption of either the movement of the linear system or the delivery of water.
Water delivery machines of the general type to which the machine of the present invention generally relates are known in the art. Examples are shown in Russian Patent No. 363,463, U.S. Pat. Nos. 4,036,436, 4,172,556, 4,274,584, and 4,412,655 and in abandoned U.S. patent application Ser. No. 06/161,678, filed June 23, 1980, in the name of Dennis R. Theilen and assigned to the same assignee as the present application, the entirety of said patents and said application being incorporated herein by reference.
The Russian patent discloses such a machine having a main tractor and two carts, each of which has a coupler mechanism for connecting and disconnecting to connectors along a main line. Each of the carts has a hydraulic motor for driving the wheels of the cart. Water is fed from the couplers to the linear system by way of articulated pipes. With the machine of the Russian patent, the two carts and the main tractor are all laterally offset.
Standal U.S. Pat. Nos. 4,036,436 and 4,172,556 disclose a water delivery machine having a main tractor and two reciprocating carts supporting couplers for connecting and disconnecting to the spaced risers as the machine moves along the pressurized main line. In one of the disclosed embodiments, the main tractor is separately powdered, and the carts are made to extend and retract with hydraulic cylinders. Water is delivered from the pressurized main line to the linear system via the couplers and the vertically oriented articulated booms.
Nobel U.S. Pat. No. 4,274,584 discloses a water delivery machine very similar to those of the Russian and Standal patents. With the machine of the Nobel patent, the outer ends of reciprocating water pipes are supported by carts, with their inner ends supported for rolling movement along an "elongated track" which is rigidly secured to the main tractor and which extends generally parallel to the pressurized main line. In a commercialized version of the machine of the Nobel patent, the flexible hoses connecting the inner ends of the water pipes to the linear system are replaced with generally horizontally disposed articulated booms as shown in Noble U.S. Pat. No. 4,412,655. With the machine of the Nobel patent, and its known commercial version, the wheels of each of the carts are driven and steered, and the wheels of the main tractor are driven, to power and guide the machine along a buried pressurized main line.
Both the systems of the Standal and Nobel patents operate in what is known as as "inch worm" fashion. That is, at one position (retracted position) in the cycle, the two couplers are connected to adjacent risers and thus span two risers, and at another position, (extended position), in the cycle, the two couplers span three risers. During operation of these machines, the carts do not pass each other, but rather each coupler connects progressively to each riser.
The machine disclosed in the Theiland application, Ser. No. 06/161,678, also has a main tractor and two reciprocating carts, each carrying a coupler for engaging and disengaging in an inch worm fashion to the spaced risers of the pressurized main line. Water is delivered from the couplers to the irrigation system via reciprocating booms connected between the carts and the main tractor, and hoses connected between the booms and the linear system. The booms are mounted to the main tractor by a rolling connection which allows the booms to reciprocate between extended and retracted positions relative to the tractor. The booms, and hence the carts and couplers, are driven between extended and retracted positions by motor and clutch drives mounted on the main tractor.
A guidance system for guiding a linear irrigation system is disclosed in Johnson U.S. Pat. No. 4,172,551 by the same inventor as the present invention, the entirety of which is incorporated herein by reference. That guidance system has been used in commercial versions to guide both ditch feed and hose drag linears, as well as those supplied water by water delivery machines.
A problem with these prior art water delivery machines, including their commercial versions, has been their expense. The farmer must not only purchase the linear irrigation system, which for example might be a single one-quarter mile (0.4023 km) system or a one-half mile (0.8046 km) system with one-half of the system on either side of the water delivery machine, but must also purchase the water delivery machine itself and the pressurized main line with all of the risers. One of the major expenses has been the risers themselves, each of which includes a valve. With riser spacings of from 44 to 50 feet (13.41 to 15.24 meters) on commercial versions, anywhere from 105 to 120 such risers may be required on a mile-long (1.609 km) field. Therefore, riser spacing becomes critical. Another problem has been the capability of such machines to operate on uneven or rough terrain.
The water delivery machine of the present invention provides improvements in both of these problem areas in providing a machine that allows for significantly greater riser spacing with added stability over rough terrain. Thus, in accordance with the present invention, the articulated booms which extend from the couplers to the linear system, include first conduit sections extending generally fore and aft in the direction of the main line with their outer ends connected to the couplers. Both the outer and inner ends of these first conduit sections are supported on wheel bogeys defining carts of substantial length. Coupling mechanisms for connection and disconnection to the risers are mounted at the outer ends of the carts. The articulated booms further include second and third conduit sections, these three sections connected together at swivel joints such that the booms articulate as the machine moves between extended and retracted positions. Preferably, the wheels of both the inner and outer wheel bogeys are steered, and one or more of the wheels of each cart are driven to extend and retract the carts relative to the main tractor and to guide the carts along a preselected path as the machine and linear system move down the field.
By supporting a substantial length of each of the booms (the first conduit section) on wheels to define a cart, a substantial portion of the articulated boom is supported on the ground. This means that the overall length of the articulated boom may be increased to provide greater riser spacing, and thus fewer risers. The boom and cart design also provides control over rougher terrain, and eliminates the need for an "elongated track" rigidly mounted to the main tractor with roller mechanisms for supporting the inner ends of the first conduit sections as with some prior art machines. Moreover, limited independent pivotal movement about an axis generally parallel to the direction of travel is provided as between the inner and outer wheel bogeys supporting each of the carts, and as between the cart frame and the conduit section supported thereon, to accomodate uneven terrain. As a result, reliable coupling and uncoupling of the couplers with the risers is achieved within acceptable limits although the main tractor and the wheel bogeys of the carts are each traveling over different terrain at a given instant of time.
The guidance system of the present invention provides accurate and reliable guidance for both the water delivery machine and the linear irrigation system. In principle, it incorporates the teachings of said Johnson U.S. Pat. No. 4,172,551 and also provides guidance off a single guide cable where the main tractor is laterally offset therefrom and from the carts.
These and other advantages of the invention are apparent from the drawing and the detailed description to follow.